diff --git a/src/experimental/tf_ring.scad b/src/experimental/tf_ring.scad
index 9e45f20f..941a3533 100644
--- a/src/experimental/tf_ring.scad
+++ b/src/experimental/tf_ring.scad
@@ -4,7 +4,7 @@ use <experimental/tf_y_twist.scad>;
 /*
     size: The size of a rectangle.
     point: A point in the rectangle.
-    radius: sphere radius.
+    radius: ring radius.
     angle: arc angle.
     twist: The number of degrees of through which the rectangle is twisted.
 */